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Why is fentanyl so dangerous?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Aug 5, 2024.

Official Answer by Drugs.com

Key takeaways:

There is no way to know how much illicit fentanyl may be contained in a drug you plan to use or how potent it is. However, fentanyl test strips are available at certain health departments or syringe exchange programs, so you can test the drug you plan to use for fentanyl. Ask your healthcare provider where you can get these strips.

Another reason fentanyl is so dangerous is that many people are simply unaware of this ongoing threat. According to the CDC, man-made opioids like fentanyl are fueling the majority of overdose deaths in the United States.

Even though an online pill identifier might show that a pill bought on the street looks like a legitimate prescription pill because it has the same color, shape or imprint code, this is most likely NOT true. Illegal drug manufacturers create fake opioid pills to look exactly like the real ones. The fake pills may also contain fentanyl, or only contain fentanyl. You cannot tell if a pill, powder, nasal spray or injection bought off of the street contains a deadly dose of any drug just by looking at it.

Opioids were involved in 68,630 overdose deaths in 2020 (74.8% of all drug overdose deaths).

Is fentanyl legal?

Yes, fentanyl is classified as a Schedule II controlled substance in the U.S. and is available by prescription only. When monitored and used as directed by your physician, it can effectively relieve severe pain. You should never use it unless it has been prescribed by a licensed medical professional who cares for you and is dispensed by a licensed pharmacy.

Legal fentanyl is a synthetic opioid medicine typically used to treat patients with long-lasting severe pain or severe pain following surgery. It is similar to morphine but about 100 times more potent. For control of cancer pain, fentanyl is only given to patients who are “opioid-tolerant”, meaning they are used to the narcotic effects of fentanyl and have already been taking around-the-clock opioids for severe cancer pain.

Related questions

How much fentanyl can kill you?

One 2 milligram (mg) dose of fentanyl is enough to kill an adult, but may be more or less depending upon your body size, opioid tolerance, and former usage. Fentanyl can kill you within a matter of 2 minutes, usually due to respiratory failure (breathing that has stopped).

Fatal dosage for fentanyl

Source: http://www.dea.gov/galleries/drug-images/fentanyl - DEA, 2022. Two milligrams of fentanyl can be a lethal dose in most people, according to the DEA.

Prescription fentanyl is dosed in micrograms, designated by the abbreviation “mcg”. This is an extremely small dose. Most other drugs are dosed in milligrams ("mg") -- for example, 500 mg of acetaminophen (Tylenol) or 25 mg of diphenhydramine (Benadryl).

According to the DEA, 42% of pills they tested for fentanyl contained at least 2 mg of fentanyl, a potentially lethal dose. Drug traffickers typically distribute fentanyl by the kilogram. One kilogram of fentanyl has the potential to kill 500,000 people.

How does fentanyl kill you?

Most people die from respiratory depression and failure from an overdose of an opioid like fentanyl. This means breathing stops altogether, and they cannot get the oxygen their brain and body need to survive. Some people may also vomit and choke to death because they are unconscious. This typically occurs rapidly, in a matter of a few minutes.

A fentanyl overdose may lead to:

If administered in time and in a sufficient dose (or doses), the opioid antidote naloxone (Narcan) may be able to reverse a fentanyl overdose and respiratory depression.

You can access naloxone from most pharmacists in the U.S. without a prescription. If you, a family member, or a friend take illegal drugs, it is important to have immediate access to naloxone to help possibly save a life. Ask your healthcare provider for more information.

Learn more: Know Your Naloxone: Save a Life

For more information, you can contact find evidence-based treatment and service options near you by visiting https://findtreatment.gov or by calling the 24/7, National Helpline at 800-662-HELP (4357).

This is not all the information you need to know about fentanyl and does not take the place of your healthcare provider's advice. Discuss this information and any questions you have with your doctor or other health care provider.

References
  • Facts about fentanyl. US Drug Enforcement Agency (DEA). Accessed Aug. 15, 2022 at https://www.dea.gov/resources/facts-about-fentanyl
  • Fentanyl. US Drug Enforcement Agency (DEA). Accessed Aug. 15, 2022 at https://www.dea.gov/factsheets/fentanyl
  • Synthetic Opioid Overdose Data. Centers for Disease Control and Prevention (CDC). Reviewed: June 6, 2022. Accessed Aug. 15, 2022 at https://www.cdc.gov/drugoverdose/deaths/synthetic/index.html
  • Fentanyl. Government of Canada. Accessed Aug. 15, 2022 at https://www.canada.ca/en/health-canada/services/substance-use/controlled-illegal-drugs/fentanyl.html
  • Fentanyl Flow to the United States. DEA. March 6, 2020. Accessed Aug 15, 2022 at https://www.dea.gov/documents/2020/2020-03/2020-03-06/fentanyl-flow-united-states

Read next

Fentanyl test strips: where to get & how to use?

Fentanyl test strips can be found at your local health department, at a community needle-exchange program, from reliable online sources, or even vending machines in some states. Once the strip is dipped into a sample of the drug (usually dissolved in a small amount of water), the results indicate if fentanyl is present. Follow the instructions for use on your specific test strips. Continue reading

What are the symptoms of a fentanyl overdose?

A fentanyl overdose may result in signs and symptoms such as:

  • stupor (dazed or nearly unconscious)
  • coma (cannot be awakened, unable to speak)
  • pupil constriction
  • slowed or absent breathing (respiratory depression or failure)
  • cyanosis (bluish or purplish tint to the skin, lips or fingernails due to low oxygen levels)
  • vomiting
  • heartbeat slows or stops
  • death
Continue reading

How does fentanyl compare to heroin or other opiates?

Fentanyl is an extremely potent, synthetic (man-made) opioid. It is about 50 times more potent than heroin and 100 times more potent than morphine. In contrast, heroin is 2 to 3 times more powerful than morphine. Fentanyl is a legally prescribed drug for pain in the US and is classified as Schedule II controlled substance when used for legitimate purposes. Heroin is illegal in the U.S. and is classified as a Schedule I controlled substance. Continue reading

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